I am unable to update Xcode ...my internet speed is quite fine...please help!!

This 100 times. I have been trying to update Xcode to version 8 for weeks via the app store and the "working" animation at the top left just keeps spinning for hours and hours. I have looked all over for a solution to this and cannot find one. Xcode, Apple get it together!

If that means via the MAS, try downloading from here as an alternative: https://developer.apple.com/download/more/

And note we're being told to avoid Xcode 8 for 8.3.1 ~ 8.3.2, instead.

— Make sure you're signed in to the Mac App Store using an Apple ID belonging to the developer program. Sometimes, it won't prompt you to login when it should.

— Sometimes the MAS app starts a download but don't give any sign that it's doing so. Based on your description, I don't think this is happening, but if you keep resetting the update, the download never finishes. Sometimes you just need to be patient.

— If you have no luck with the MAS download, you should be able to download it as a disk image here:

developer.apple.com/downloads

in the Developer Tools category. (Note the "s" on downloads.)